Edjewmakation...

I actually know quite a bit about photography, but I did not understand the question. Depth of field is a function of the F stop and distance from the subject(s). For instance, If it is daylight and you have a person standing 10 feet away from you and a car behind them 40 feet from you, and you leave your lens on F1.4, you will have to use a fast shutter speed. With that 1.4 lens opening, you can either have the car be in focus and the person a bit fuzzy, or the person in focus and the car a bit fuzzy. The 1.4 F stop will give you a shallow depth of field. However, you could go to a slower shutter speed and a smaller F stop combination (say 1/60 second and F22) that will give you the same exposure, but a much deeper depth of field. You could probably get both the car and the person in focus. Most lenses have a depth of field gauge on them that can be quite useful. The same idea could be used to have the rear of the red Chevelle in focus and the front a bit fuzzy. However, other than kind of understanding what you mean by liking soft rear ends (I'm sure their is a great joke there), I'm not sure what the actual question is.